Signaling system



1,634,941 July 1927' E. M. HEWLETT ET AL SIGNALING SYSTEM Filed Nov. 22. 1924 di d 2/ Inventors:

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Patented July 5, 1927. 1

UNI-TED sT 'rss PATENT OFFICE;

EDWARD I. HEWLETT AND WALDO W. WILLARD, OI SCHENECTADY, -NEW YORK, AS- SIGNORS TO GENERAL ELECTBIC'OOHPAN Y, A CORPORATION NEW YORK.

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I Application 'nled November 28, I884. 8eria1.ll'o. 751,713. v

I Our invention relates t e signaling systems and .has for its object the rovision of means for indicating the operatlon of a protective device in an electric, circuit.

More specifically, ourinvention relates to .15 tective device operates, one of the transformers is de-energized and the other transformer thereby caused to operate a suitable signal, such as an electric light,

For a more complete understanding of accompanying drawing, in the single figure of which is shown indiagrammatic fashion a signaling system embodying our invention.-

Referring to the drawing, we have shown our invention in one form as applied to an alternating current electric supply source comprising supply mains 10 and 11 and leading to a translating device to which electric ener is supplied, such as an electric motor 12. onnected in the mains '10 and 11' is suitableprotective means, shown as fuses 13 and 14, whereby the supply circuit is opened upon the occurrence of abnormal conditions, such as a short circuit in the electric motor 12.

In accordance with our invention, we ro-.

vvide means whereby a signal is given w en the supply circuit is'opened by the blowing of one or both of tlie'fuses 13 and 14. Transformers l5 and 16 are provided havin their primary windings 17 and 18 connecte to the suppl mains 10 and 11 on opposite sides of the 1 windin s 19 and 20 of the transformers haye equal e ectromotive' forces induced therein and are connected in series in a closed c1r cuit in opposition to each other, 1. e., the

terminals of the secondary having like g1 polarities are connected together. Interposed in the connections between the secondary windings isa suitable signaling device, such as an electric lamp 21. I

As thus constructed and'arranged 1! null 56 be observed that under normal conditions e like, is

heat the electric motor from the source of our invention reference should be had to the.

ses 13 and 14. The secondary ofoperation, electric ene being supplied through the fuses to the e ectric motor, the two transformers will be energized and since their secondaries are connected in oppositmnnmdifi'e'rence of potential will be impressed onthe lamp 21. The lamp, therefore will not li ht. Upon the occurrence of abnormal con itions causing one or' both of the-fuses 13 andl to blow, and-disconsupply, itiwill be observed that the transformer 'lfi will be de-energized; As a result,-

there will be no electromotive force of secondary winding 20 in opposition to the electromotive force of secondary winding 19 and therefore the voltage of winding 19 i will be applied to the lamp 21, .whereby it'is caused to light. and thus indicate that thesupply circuit has been opened by the operation of one or both of the protective fuses 13 and P1.

While we have described our invention as embodied in concrete form and as operating in a specific manner in accordance -with the provisions of the patent statutes, it should '80 e understood that we do not limit our invention thereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of our invention, the scope of which is set forth in the annexed claims.

What we claim as new and desire to secure by Letters Patent of the United; States, is:---'- 1. A signaling system comprising in comm bination with alternating'current electrical supply mains or the like, pr'otectivemeans for opening the circuit throughsaid supply mains upon the occurrence of abnormal con ditions therein, a pair of transformers connected to said supply mains on opposite sides of said protective means respectively, whereby one of said,transfo'rmers is de-energized upon the operation of said protective means,

connections whereby the output circuits of said transformers are connected in opposi tion, a signaling device operated by one of said transformers when theother is 'deener- 'zed; a

2. A sign-alin system comprising in combination with ternating current electrical supply mains or the like, protective'means for opening the circuit through said supply mains u y n the occurrence of abnormal conditions erein, a pair of transformers each including a primary and a secondary winding, connections between said primary windings and said supply mains on opposite sides of said protective means respectively, electrical connections between said secondaries whereby said secondaries are connected in opposition, and a signaling device operated by one of said secondaries when the other is de-energized by the operation of said protective means.

3. A signaling system comprising in combination with alternating current electrical supply mains or the like, protective-means for opening the circuit through said supply mains upon the occurrence of abnormal conditions therein, a pair of transformers each including a primary and a secondary wlnd- 1ng,connect1ons between said primary windings and said supply mains on opposite sides of said protective means respectively, electrical connections whereby said secondaries are connected in opposition to each other in a closed circuit, and a signaling device included in said circuit with said secondaries so as to be operated by one of said secondaries when the other is de-energized by the operation of said protective means.

4. A signaling system comprising in combination with alternating current electrical supply mains or the like, fuses in said mains,

a pair of transformers, each including a primary and secondary winding, connections between said primary windings and said supply source on opposite sides of said fuses respectively, connections whereby said secondaries are connected in opposition to each other in a closed circuit, and a signaling device interposed in said circuit with said secondaries so as to be operated by one of said transformers when the primary circuit of the other transformer is opened by the blowing of one or both of said fuses.

In witness whereof, we have hereunto set our hands this 21st day of November 1924.

' EDWARD M. HE\VLETT.' WALDO W. WILLARD. 

